332 LIFE AND DEATH. 



Destruction of the Social Individual due to Extrinsic 

 Causes, As for the destruction, the death of this 

 social individual, of this hundred-year-old tree, it 

 seems indeed that there is no ground for considering 

 it a natural necessity. We find the sufficient reason 

 of its usual end in the repercussion on the individual 

 of external and contingent circumstances. The cause 

 of the death of a tree, of an oak many centuries old, 

 is to be found in the ambient conditions, and not in 

 some internal condition. Cold and heat, damp and 

 dryness, the weight of the snow, the mechanical 

 action of the rain, of hail, of winds unchained, of 

 lightning; the ravages of insects and parasites 

 these are what really work its ruin. And further, 

 the new branches, appearing every year and increas- 

 ing the load the trunk has to bear, increase the 

 pressure of the parts, and make more difficult the 

 motion of the sap. But for these obstacles, external, 

 so to speak, to the vegetable being itself, it would 

 continue indefinitely to bloom, to fructify, and as 

 each spring returned to show fresh buds. 



Difficulty of Interpretation. In this as in all other 

 examples we must know the nature of the beings that 

 we see lasting on and braving the centuries. Is it the 

 individual? Is it the species? Is it a living being, 

 properly so called, having its unity and its in- 

 dividuality, or is it a series of generations succeeding 

 one another in time and extending in space? In a 

 word, the question is one of knowing if we have to do 

 with a real tree or with a genealogical tree. We are 

 just as uncertain when we deal with animals. What 

 is the being that lasts on a series of generations or 

 an individual? This doubt forbids us to draw any 

 conclusion from the observation of complex beings. 



